1. Field of the Invention
The present invention relates to machines for processing meat. More particularly, it relates to a processor for penetrating the meat to puncture the muscles and connective tissue of the meat, to break up rigor mortis in the meat and tenderize it, to release the meat proteins, and to affect a better distribution, retention, and absorption of the curing fluids in the meat.
2. Description of the Prior Art
For some years it has been known that if the natural proteins of the meat can be released and diffused throughout the meat, these proteins will serve as a binder when the meat pieces are pressed together and cooked so that pieces of meat and boneless meats can be reformed into an integral mass. It has also been known that puncturing, crushing, mashing, slitting, beating, massaging, tumbling and agitation of the meat in the presence of a curing solution will cause these meat proteins to be released.
The puncturing and crushing of the meat pieces which have undergone rigor mortis also has the effect of breaking the connective tissue and crushing the internal cells of the meat to make it more pliable. The puncturing of the meat also allows the curing solution to penetrate more deeply into the piece of meat where it is more uniformly absorbed, thus leading to a more consistent ultimate product.
It has been found that it is particularly desirable to puncture the meat as deeply as possible while subjecting it to pressure. If the meat is compressed while it is punctured, the cure solution will penetrate more deeply and uniformly throughout the meat even though the meat expands after the pressure is released. It has been found that deep penetration under pressure allows the meat to retain more of the cure fluids and soluble proteins during and after subsequent processing steps than by merely opening the surface of the meat.
Some of the prior art machines treat the surface of pieces of meat by passing the meat between a roller and a plate and puncturing, squeezing or slitting it. A problem with these machines is that usually the plate is disposed in a fixed position which cannot be easily adjusted, if at all, to accommodate meat pieces which are different sizes from those for which the spacing between the roller and the plate is set. Many pieces of meat will receive either an insufficient treatment from the roller or will be too large and will jam the machine.
One attempt to correct the problems resulting from the fixed plate has been to make the plate out of a flexible metal which would distort with respect to the roller when larger pieces of meat are passed between the roller and the plate. However, such a plate has been found to be limited in its durability and in the amount of pressure it could withstand. Another attempt to solve the problem was to mount a rigid heavier duty plate on springs which could be individually adjusted to change the spacing of the plate with respect to the roller for different size meats to maintain a relatively consistent pressure on each size of meat. However, such adjustments are only possible when the machine is not processing meat, and since most meat processing machines have to be regularly disassembled for cleaning each day, it has been found to be very inconvenient to reset the spring tension after each cleaning, as well as to take the time to do so whenever different sized pieces of meat were processed. The inconvenience resulted in the failure by many operators to make the required adjustments whereby processing of the meat by these machines could prove to be unsatisfactory.
There was thus a need for a machine which would allow variable pressure adjustments of the plate with respect to the roller while the machine was in operation that would still distribute uniform pressure over the entire piece of meat of varying sizes so that there would be a consistent uniform product.
Any machine which utilizes a roller to crush or open the surface of a piece of meat will also have inherent safety risks for the operators, particularly when a large volume of meat pieces is to be run through a machine at a high speed. Since meat processors must process large volumes of meat to justify the capital expenditures for equipment to remain competitive, they ordinarily demand a high volume capability of their machines.
The machine of the present invention solves these problems of the prior art and can be adjusted to uniformly squeeze and puncture pieces of meat to a maximum depth under a consistent amount of pressure regardless of the size of the meat pieces. The machine of the present invention allows the operator to quickly and easily control the pressure placed on the meat passing between the roller and the plate by a single control while the machine continues in operation. The meat is passed between a roller having sharp, radial projections and an easily adjustable variable pressure plate. When the plate is set for a relatively high pressure, it produces a deep penetration of the meat by the roller regardless of the size of the meat with a pressure which is uniformly distributed on the piece of meat. The benefits of deep penetration and even pressure results in uniformly pliable pieces of meat with a more even cure distribution, with better absorption and retention of the curing solution. This produces a more uniform and consistent product from batch to batch while still allowing a high degree of efficiency and speed in processing the meat.
The present invention also provides a solution to some of the safety problems of a high volume processing machine by the incorporation of a conveyor system with a safety cover which allows operators to load a large quantity of meat onto the conveyor for processing through the machine while minimizing their exposure to the roller when the machine is in operation. The conveyor, while reducing safety concerns, also allows more meat to be fed into the machine at one time and contributes to its efficiency.
In addition, it has been found that this machine is useful for treating meat to shorten the total processing time of subsequent tumbling or shaking and tumbling steps as described in pending U.S. patent applications, Ser. Nos. 213,533 and 213,554, wherein it is noted that this sequence of steps increases the capability of the meat to absorb and retain fluids, including soluble proteins, thus resulting in a higher yield and a more tender, uniform, and nutritious product that is firmly bonded into whole pieces.